diff --git a/client/global.go b/client/global.go
index 11144b9e7..1a2c661c9 100644
--- a/client/global.go
+++ b/client/global.go
@@ -395,8 +395,10 @@ func (info *DeviceInfo) GenNewGuid() {
 func (info *DeviceInfo) GenNewTgtgtKey() {
 	r := make([]byte, 16)
 	rand.Read(r)
-	t := md5.Sum(append(r, info.Guid...))
-	info.TgtgtKey = t[:]
+	h := md5.New()
+	h.Write(r)
+	h.Write(info.Guid)
+	info.TgtgtKey = h.Sum(nil)
 }
 
 func (info *DeviceInfo) GenDeviceInfoData() []byte {
diff --git a/client/group_info.go b/client/group_info.go
index 572662a78..2d9c10a8f 100644
--- a/client/group_info.go
+++ b/client/group_info.go
@@ -8,14 +8,15 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/pkg/errors"
+	"google.golang.org/protobuf/proto"
+
 	"github.com/Mrs4s/MiraiGo/binary"
 	"github.com/Mrs4s/MiraiGo/binary/jce"
 	"github.com/Mrs4s/MiraiGo/client/pb/oidb"
 	"github.com/Mrs4s/MiraiGo/client/pb/profilecard"
 	"github.com/Mrs4s/MiraiGo/protocol/packets"
 	"github.com/Mrs4s/MiraiGo/utils"
-	"github.com/pkg/errors"
-	"google.golang.org/protobuf/proto"
 )
 
 type (
diff --git a/client/group_msg.go b/client/group_msg.go
index 2d31f148a..31e1be8f8 100644
--- a/client/group_msg.go
+++ b/client/group_msg.go
@@ -350,15 +350,12 @@ func decodeMsgSendResponse(c *QQClient, _ *incomingPacketInfo, payload []byte) (
 	if err := proto.Unmarshal(payload, &rsp); err != nil {
 		return nil, errors.Wrap(err, "failed to unmarshal protobuf message")
 	}
-	if rsp.GetResult() != 0 {
-		switch rsp.GetResult() {
-		case 55:
-			c.Error("send msg error: %v Bot has blocked target's content", rsp.GetResult())
-			break
-		default:
-			c.Error("send msg error: %v %v", rsp.GetResult(), rsp.GetErrMsg())
-			break
-		}
+	switch rsp.GetResult() {
+	case 0: // OK.
+	case 55:
+		c.Error("send msg error: %v Bot has blocked target's content", rsp.GetResult())
+	default:
+		c.Error("send msg error: %v %v", rsp.GetResult(), rsp.GetErrMsg())
 	}
 	return nil, nil
 }
diff --git a/client/highway.go b/client/highway.go
index a64bf6695..9aa6230e2 100644
--- a/client/highway.go
+++ b/client/highway.go
@@ -4,10 +4,8 @@ import (
 	"bytes"
 	"crypto/md5"
 	binary2 "encoding/binary"
-	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"os"
@@ -46,10 +44,10 @@ func (c *QQClient) highwayUploadStream(ip uint32, port int, updKey []byte, strea
 	defer conn.Close()
 	offset := 0
 	reader := binary.NewNetworkReader(conn)
-	chunk := *binary.Get256KBytes()
-	defer func() { // 延迟捕获 chunk
-		binary.Put256KBytes(&chunk)
-	}()
+	buf := binary.Get256KBytes()
+	chunk := *buf
+	defer binary.Put256KBytes(buf)
+
 	w := binary.NewWriter()
 	defer binary.PutWriter(w)
 	for {
@@ -131,10 +129,10 @@ func (c *QQClient) highwayUploadByBDH(stream io.Reader, length int64, cmdId int3
 		return nil, errors.Wrap(err, "echo error")
 	}
 	var rspExt []byte
-	chunk := *binary.Get256KBytes()
-	defer func() { // 延迟捕获 chunk
-		binary.Put256KBytes(&chunk)
-	}()
+	buf := binary.Get256KBytes()
+	chunk := *buf
+	defer binary.Put256KBytes(buf)
+
 	w := binary.NewWriter()
 	defer binary.PutWriter(w)
 	for {
@@ -466,7 +464,8 @@ func (c *QQClient) excitingUploadStream(stream io.ReadSeeker, cmdId int32, ticke
 		if err != nil {
 			return nil, errors.Wrap(err, "request error")
 		}
-		body, _ := ioutil.ReadAll(rsp.Body)
+		body, _ := io.ReadAll(rsp.Body)
+		_ = rsp.Body.Close()
 		r := binary.NewReader(body)
 		r.ReadByte()
 		hl := r.ReadInt32()
@@ -487,32 +486,6 @@ func (c *QQClient) excitingUploadStream(stream io.ReadSeeker, cmdId int32, ticke
 	return rspExt, nil
 }
 
-// 只是为了写的跟上面一样长(bushi，当然也应该是最快的玩法
-func (c *QQClient) uploadPtt(ip string, port int32, updKey, fileKey, data, md5 []byte) error {
-	url := make([]byte, 512)[:0]
-	url = append(url, "http://"...)
-	url = append(url, ip...)
-	url = append(url, ':')
-	url = strconv.AppendInt(url, int64(port), 10)
-	url = append(url, "/?ver=4679&ukey="...)
-	p := len(url)
-	url = url[:p+len(updKey)*2]
-	hex.Encode(url[p:], updKey)
-	url = append(url, "&filekey="...)
-	p = len(url)
-	url = url[:p+len(fileKey)*2]
-	hex.Encode(url[p:], fileKey)
-	url = append(url, "&filesize="...)
-	url = strconv.AppendInt(url, int64(len(data)), 10)
-	url = append(url, "&bmd5="...)
-	p = len(url)
-	url = url[:p+32]
-	hex.Encode(url[p:], md5)
-	url = append(url, "&mType=pttDu&voice_encodec=1"...)
-	_, err := utils.HttpPostBytes(string(url), data)
-	return errors.Wrap(err, "failed to upload ptt")
-}
-
 func (c *QQClient) uploadGroupHeadPortrait(groupCode int64, img []byte) error {
 	url := fmt.Sprintf(
 		"http://htdata3.qq.com/cgi-bin/httpconn?htcmd=0x6ff0072&ver=5520&ukey=%v&range=0&uin=%v&seq=23&groupuin=%v&filetype=3&imagetype=5&userdata=0&subcmd=1&subver=101&clip=0_0_0_0&filesize=%v",
diff --git a/client/image.go b/client/image.go
index 0d43408e7..2b1662db9 100644
--- a/client/image.go
+++ b/client/image.go
@@ -47,7 +47,7 @@ func (c *QQClient) UploadGroupImage(groupCode int64, img io.ReadSeeker) (*messag
 	}
 	if len(c.srvSsoAddrs) == 0 {
 		for i, addr := range rsp.UploadIp {
-			c.srvSsoAddrs = append(c.srvSsoAddrs, fmt.Sprintf("%v:%v", binary.UInt32ToIPV4Address(uint32(addr)), rsp.UploadPort[i]))
+			c.srvSsoAddrs = append(c.srvSsoAddrs, fmt.Sprintf("%v:%v", binary.UInt32ToIPV4Address(addr), rsp.UploadPort[i]))
 		}
 	}
 	if _, err = c.highwayUploadByBDH(img, length, 2, rsp.UploadKey, fh, EmptyBytes, false); err == nil {
@@ -74,7 +74,7 @@ func (c *QQClient) UploadGroupImageByFile(groupCode int64, path string) (*messag
 	}
 	defer func() { _ = img.Close() }()
 	fh, length := utils.ComputeMd5AndLength(img)
-	seq, pkt := c.buildGroupImageStorePacket(groupCode, fh[:], int32(length))
+	seq, pkt := c.buildGroupImageStorePacket(groupCode, fh, int32(length))
 	r, err := c.sendAndWait(seq, pkt)
 	if err != nil {
 		return nil, err
@@ -105,7 +105,7 @@ ok:
 	if bytes.Equal(tmp, []byte{0x47, 0x49, 0x46, 0x38}) {
 		imageType = 2000
 	}
-	return message.NewGroupImage(binary.CalculateImageResourceId(fh[:]), fh[:], rsp.FileId, int32(length), int32(i.Width), int32(i.Height), imageType), nil
+	return message.NewGroupImage(binary.CalculateImageResourceId(fh), fh, rsp.FileId, int32(length), int32(i.Width), int32(i.Height), imageType), nil
 }
 
 func (c *QQClient) UploadPrivateImage(target int64, img io.ReadSeeker) (*message.FriendImageElement, error) {
diff --git a/client/online_push.go b/client/online_push.go
index 4b93f1445..ede6ca3ac 100644
--- a/client/online_push.go
+++ b/client/online_push.go
@@ -229,35 +229,37 @@ func msgType0x210Sub44Decoder(c *QQClient, protobuf []byte) error {
 	if err := proto.Unmarshal(protobuf, &s44); err != nil {
 		return errors.Wrap(err, "failed to unmarshal protobuf message")
 	}
-	if s44.GroupSyncMsg != nil {
-		func() {
-			groupJoinLock.Lock()
-			defer groupJoinLock.Unlock()
-			if s44.GroupSyncMsg.GetGrpCode() != 0 { // member sync
-				c.Debug("syncing members.")
-				if group := c.FindGroup(s44.GroupSyncMsg.GetGrpCode()); group != nil {
-					group.Update(func(_ *GroupInfo) {
-						var lastJoinTime int64 = 0
-						for _, m := range group.Members {
-							if lastJoinTime < m.JoinTime {
-								lastJoinTime = m.JoinTime
-							}
-						}
-						if newMem, err := c.GetGroupMembers(group); err == nil {
-							group.Members = newMem
-							for _, m := range newMem {
-								if lastJoinTime < m.JoinTime {
-									go c.dispatchNewMemberEvent(&MemberJoinGroupEvent{
-										Group:  group,
-										Member: m,
-									})
-								}
-							}
-						}
+	if s44.GroupSyncMsg == nil {
+		return nil
+	}
+	groupJoinLock.Lock()
+	defer groupJoinLock.Unlock()
+	if s44.GroupSyncMsg.GetGrpCode() != 0 { // member sync
+		return errors.New("invalid group code")
+	}
+	c.Debug("syncing members.")
+	if group := c.FindGroup(s44.GroupSyncMsg.GetGrpCode()); group != nil {
+		group.lock.Lock()
+		defer group.lock.Unlock()
+
+		var lastJoinTime int64 = 0
+		for _, m := range group.Members {
+			if lastJoinTime < m.JoinTime {
+				lastJoinTime = m.JoinTime
+			}
+		}
+
+		if newMem, err := c.GetGroupMembers(group); err == nil {
+			group.Members = newMem
+			for _, m := range newMem {
+				if lastJoinTime < m.JoinTime {
+					go c.dispatchNewMemberEvent(&MemberJoinGroupEvent{
+						Group:  group,
+						Member: m,
 					})
 				}
 			}
-		}()
+		}
 	}
 	return nil
 }
diff --git a/client/ptt.go b/client/ptt.go
index ff9eacd29..bb911f481 100644
--- a/client/ptt.go
+++ b/client/ptt.go
@@ -353,19 +353,3 @@ func decodeGroupShortVideoUploadResponse(_ *QQClient, _ *incomingPacketInfo, pay
 	}
 	return rsp.PttShortVideoUploadRsp, nil
 }
-
-func constructPTTExtraInfo(codec, length int32) []byte {
-	return binary.NewWriterF(func(w *binary.Writer) {
-		w.WriteByte(3)
-		w.WriteByte(8)
-		w.WriteUInt16(4)
-		w.WriteUInt32(uint32(codec))
-		w.WriteByte(9)
-		w.WriteUInt16(4)
-		w.WriteUInt32(uint32(14)) // length 时间
-		w.WriteByte(10)
-		info := []byte{0x08, 0x00, 0x28, 0x00, 0x38, 0x00} // todo
-		w.WriteUInt16(uint16(len(info)))
-		w.Write(info)
-	})
-}
diff --git a/client/qidian.go b/client/qidian.go
index c633f5de1..be8eef545 100644
--- a/client/qidian.go
+++ b/client/qidian.go
@@ -4,7 +4,7 @@ package client
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 
 	"github.com/pkg/errors"
@@ -144,7 +144,8 @@ func (c *QQClient) bigDataRequest(subCmd uint32, req proto.Message) ([]byte, err
 	if err != nil {
 		return nil, errors.Wrap(err, "request error")
 	}
-	rspBody, _ := ioutil.ReadAll(rsp.Body)
+	defer rsp.Body.Close()
+	rspBody, _ := io.ReadAll(rsp.Body)
 	r := binary.NewReader(rspBody)
 	r.ReadByte()
 	l1 := int(r.ReadInt32())
diff --git a/message/message.go b/message/message.go
index a5f9fbc4c..ca60aeb1a 100644
--- a/message/message.go
+++ b/message/message.go
@@ -430,7 +430,7 @@ func ParseMessageElems(elems []*msg.Elem) []IMessageElement {
 			}
 			if content != "" {
 				if elem.RichMsg.GetServiceId() == 35 {
-					reg := regexp.MustCompile(`m_resid="(\w+?.*?)"`)
+					reg := regexp.MustCompile(`m_resid="(.+)"`)
 					sub := reg.FindAllStringSubmatch(content, -1)
 					if len(sub) > 0 && len(sub[0]) > 1 {
 						res = append(res, &ForwardElement{ResId: reg.FindAllStringSubmatch(content, -1)[0][1]})
diff --git a/message/pack.go b/message/pack.go
index 36401be32..ac416a43d 100644
--- a/message/pack.go
+++ b/message/pack.go
@@ -230,7 +230,6 @@ func (e *GroupShowPicElement) Pack() (r []*msg.Elem) {
 			Size:      &e.Size,
 			Md5:       e.Md5,
 			Flag:      []byte{0x11, 0x00, 0x00, 0x00},
-			// OldData:  imgOld,
 			PbReserve: reserve,
 		},
 	})
diff --git a/protocol/tlv/tlv.go b/protocol/tlv/tlv.go
index 7de80968a..9bed87bdd 100644
--- a/protocol/tlv/tlv.go
+++ b/protocol/tlv/tlv.go
@@ -1,7 +1,7 @@
 package tlv
 
 func GuidFlag() uint32 {
-	var flag uint32 = 0
+	var flag uint32
 	flag |= 1 << 24 & 0xFF000000
 	flag |= 0 << 8 & 0xFF00
 	return flag
diff --git a/utils/sys.go b/utils/sys.go
index f7d587dad..3ebda44c2 100644
--- a/utils/sys.go
+++ b/utils/sys.go
@@ -31,7 +31,7 @@ func ComputeMd5AndLength(r io.Reader) ([]byte, int64) {
 	h := md5.New()
 	length, _ := io.Copy(h, r)
 	fh := h.Sum(nil)
-	return fh[:], length
+	return fh, length
 }
 
 func (r *multiReadSeeker) Read(p []byte) (int, error) {